Jailed US student Otto Warmbier released by North Korea

US student Otto Warmbier has been released from incarceration in North Korea, Secretary of State Rex Tillerson has confirmed.

According to The Independent, Tillerson said: "At the direction of [Donald Trump], the Department of State has secured the release of Otto Warmbier from North Korea."

Warmbier was serving a 15-year hard labour sentence for stealing a hotel sign, having been sentenced in March 2016. He is now reported to be on his way back to the US.

The Washington Post, citing Warmbier's father, says he is being medically evacuated from North Korea as he is in a coma. The report claims his parents were told their son contracted botulism, a rare but devastating condition that attacks the nervous system, shortly after his trial last year.

It has also been suggested Warmbier's release could be linked to the arrival of US basketball star Dennis Rodman in the country. Rodman visited North Korea in 2013 and 2014 and is a friend of leader Kim Jong-un.

When the former basketball player arrived he said he was visiting as a private citizen, but wants to bring sports to the country.

Currently three other American citizens are being held in North Korea, Kim Sang-duk, Kim Dong-chul and Kim Hak-song, the BBC reports.